The invention relates generally to power-driven conveyors and, more particularly, to conveyors using conveyor belts or chains with retractable wall segments.
Sideguards attached at the side of a conveyor belt confine conveyed articles on the belt's conveying surface by forming a barrier that prevents articles from falling off the side of the belt. In some applications, such as sorting, a belt, such as an oblique-roller belt having rollers arranged to rotate oblique to the direction of belt travel, pushes articles conveyed atop the belt rollers toward a side of the belt to transfer to other conveyors or sorting stations at transfer points along the length of the conveyor. Sideguards are not used on the transfer sides of sorting belts because they would interfere with the side-off transfer. Consequently, side rails on the conveyor frame are positioned along the side of the conveyor between transfer points to confine articles to the belt. In other applications, such as 1:2 switching, an oblique-roller belt's rollers are selectively activated to push articles to one side of the belt or the other against sideguards or side rails to form two lanes of articles. The side guards or side rails index the articles in each lane for end-off transfer to two parallel outfeed conveyors. But switches feeding more than two outfeed conveyors require the accurate formation of lanes of products within the interior of the conveyor away from the sideguards and side rails.